864dfacced
* Move files from keystone folder into appropriate folders * Move tests from keystone into appropriate folders * Fix imports to use the new module locations * Add a _i18n.py to help with localication * Add a BaseTestcase class * Add a exceptions module All just enough to run the tests. Though some tests were commented with a FIXME to be fixed in later commits. A few additional tests were not working with py34 and they are skipped using testtools.skipIf statements. Change-Id: Ib494d2a960cab5959c2adaca1eb0739fe65d14f1
245 lines
9.0 KiB
Python
245 lines
9.0 KiB
Python
# Copyright 2014 Mirantis Inc
|
|
# All Rights Reserved.
|
|
#
|
|
# Licensed under the Apache License, Version 2.0 (the "License"); you may
|
|
# not use this file except in compliance with the License. You may obtain
|
|
# a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing, software
|
|
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
# License for the specific language governing permissions and limitations
|
|
# under the License.
|
|
|
|
"""Thread-safe connection pool for python-memcached."""
|
|
|
|
# NOTE(yorik-sar): this file is copied between keystone and keystonemiddleware
|
|
# and should be kept in sync until we can use external library for this.
|
|
|
|
import collections
|
|
import contextlib
|
|
import itertools
|
|
import logging
|
|
import threading
|
|
import time
|
|
|
|
import memcache
|
|
from oslo_log import log
|
|
from six.moves import queue, zip
|
|
|
|
from oslo_cache._i18n import _
|
|
from oslo_cache import exception
|
|
|
|
|
|
LOG = log.getLogger(__name__)
|
|
|
|
|
|
class _MemcacheClient(memcache.Client):
|
|
"""Thread global memcache client
|
|
|
|
As client is inherited from threading.local we have to restore object
|
|
methods overloaded by threading.local so we can reuse clients in
|
|
different threads
|
|
"""
|
|
__delattr__ = object.__delattr__
|
|
__getattribute__ = object.__getattribute__
|
|
__new__ = object.__new__
|
|
__setattr__ = object.__setattr__
|
|
|
|
def __del__(self):
|
|
pass
|
|
|
|
|
|
_PoolItem = collections.namedtuple('_PoolItem', ['ttl', 'connection'])
|
|
|
|
|
|
class ConnectionPool(queue.Queue):
|
|
"""Base connection pool class
|
|
|
|
This class implements the basic connection pool logic as an abstract base
|
|
class.
|
|
"""
|
|
def __init__(self, maxsize, unused_timeout, conn_get_timeout=None):
|
|
"""Initialize the connection pool.
|
|
|
|
:param maxsize: maximum number of client connections for the pool
|
|
:type maxsize: int
|
|
:param unused_timeout: idle time to live for unused clients (in
|
|
seconds). If a client connection object has been
|
|
in the pool and idle for longer than the
|
|
unused_timeout, it will be reaped. This is to
|
|
ensure resources are released as utilization
|
|
goes down.
|
|
:type unused_timeout: int
|
|
:param conn_get_timeout: maximum time in seconds to wait for a
|
|
connection. If set to `None` timeout is
|
|
indefinite.
|
|
:type conn_get_timeout: int
|
|
"""
|
|
# super() cannot be used here because Queue in stdlib is an
|
|
# old-style class
|
|
queue.Queue.__init__(self, maxsize)
|
|
self._unused_timeout = unused_timeout
|
|
self._connection_get_timeout = conn_get_timeout
|
|
self._acquired = 0
|
|
|
|
def _create_connection(self):
|
|
"""Returns a connection instance.
|
|
|
|
This is called when the pool needs another instance created.
|
|
|
|
:returns: a new connection instance
|
|
|
|
"""
|
|
raise NotImplementedError
|
|
|
|
def _destroy_connection(self, conn):
|
|
"""Destroy and cleanup a connection instance.
|
|
|
|
This is called when the pool wishes to get rid of an existing
|
|
connection. This is the opportunity for a subclass to free up
|
|
resources and cleaup after itself.
|
|
|
|
:param conn: the connection object to destroy
|
|
|
|
"""
|
|
raise NotImplementedError
|
|
|
|
def _debug_logger(self, msg, *args, **kwargs):
|
|
if LOG.isEnabledFor(logging.DEBUG):
|
|
thread_id = threading.current_thread().ident
|
|
args = (id(self), thread_id) + args
|
|
prefix = 'Memcached pool %s, thread %s: '
|
|
LOG.debug(prefix + msg, *args, **kwargs)
|
|
|
|
@contextlib.contextmanager
|
|
def acquire(self):
|
|
self._debug_logger('Acquiring connection')
|
|
try:
|
|
conn = self.get(timeout=self._connection_get_timeout)
|
|
except queue.Empty:
|
|
raise exception.UnexpectedError(
|
|
_('Unable to get a connection from pool id %(id)s after '
|
|
'%(seconds)s seconds.') %
|
|
{'id': id(self), 'seconds': self._connection_get_timeout})
|
|
self._debug_logger('Acquired connection %s', id(conn))
|
|
try:
|
|
yield conn
|
|
finally:
|
|
self._debug_logger('Releasing connection %s', id(conn))
|
|
self._drop_expired_connections()
|
|
try:
|
|
# super() cannot be used here because Queue in stdlib is an
|
|
# old-style class
|
|
queue.Queue.put(self, conn, block=False)
|
|
except queue.Full:
|
|
self._debug_logger('Reaping exceeding connection %s', id(conn))
|
|
self._destroy_connection(conn)
|
|
|
|
def _qsize(self):
|
|
if self.maxsize:
|
|
return self.maxsize - self._acquired
|
|
else:
|
|
# A value indicating there is always a free connection
|
|
# if maxsize is None or 0
|
|
return 1
|
|
|
|
# NOTE(dstanek): stdlib and eventlet Queue implementations
|
|
# have different names for the qsize method. This ensures
|
|
# that we override both of them.
|
|
if not hasattr(queue.Queue, '_qsize'):
|
|
qsize = _qsize
|
|
|
|
def _get(self):
|
|
if self.queue:
|
|
conn = self.queue.pop().connection
|
|
else:
|
|
conn = self._create_connection()
|
|
self._acquired += 1
|
|
return conn
|
|
|
|
def _drop_expired_connections(self):
|
|
"""Drop all expired connections from the right end of the queue."""
|
|
now = time.time()
|
|
while self.queue and self.queue[0].ttl < now:
|
|
conn = self.queue.popleft().connection
|
|
self._debug_logger('Reaping connection %s', id(conn))
|
|
self._destroy_connection(conn)
|
|
|
|
def _put(self, conn):
|
|
self.queue.append(_PoolItem(
|
|
ttl=time.time() + self._unused_timeout,
|
|
connection=conn,
|
|
))
|
|
self._acquired -= 1
|
|
|
|
|
|
class MemcacheClientPool(ConnectionPool):
|
|
def __init__(self, urls, arguments, **kwargs):
|
|
# super() cannot be used here because Queue in stdlib is an
|
|
# old-style class
|
|
ConnectionPool.__init__(self, **kwargs)
|
|
self.urls = urls
|
|
self._arguments = arguments
|
|
# NOTE(morganfainberg): The host objects expect an int for the
|
|
# deaduntil value. Initialize this at 0 for each host with 0 indicating
|
|
# the host is not dead.
|
|
self._hosts_deaduntil = [0] * len(urls)
|
|
|
|
def _create_connection(self):
|
|
return _MemcacheClient(self.urls, **self._arguments)
|
|
|
|
def _destroy_connection(self, conn):
|
|
conn.disconnect_all()
|
|
|
|
def _get(self):
|
|
# super() cannot be used here because Queue in stdlib is an
|
|
# old-style class
|
|
conn = ConnectionPool._get(self)
|
|
try:
|
|
# Propagate host state known to us to this client's list
|
|
now = time.time()
|
|
for deaduntil, host in zip(self._hosts_deaduntil, conn.servers):
|
|
if deaduntil > now and host.deaduntil <= now:
|
|
host.mark_dead('propagating death mark from the pool')
|
|
host.deaduntil = deaduntil
|
|
except Exception:
|
|
# We need to be sure that connection doesn't leak from the pool.
|
|
# This code runs before we enter context manager's try-finally
|
|
# block, so we need to explicitly release it here.
|
|
# super() cannot be used here because Queue in stdlib is an
|
|
# old-style class
|
|
ConnectionPool._put(self, conn)
|
|
raise
|
|
return conn
|
|
|
|
def _put(self, conn):
|
|
try:
|
|
# If this client found that one of the hosts is dead, mark it as
|
|
# such in our internal list
|
|
now = time.time()
|
|
for i, host in zip(itertools.count(), conn.servers):
|
|
deaduntil = self._hosts_deaduntil[i]
|
|
# Do nothing if we already know this host is dead
|
|
if deaduntil <= now:
|
|
if host.deaduntil > now:
|
|
self._hosts_deaduntil[i] = host.deaduntil
|
|
self._debug_logger(
|
|
'Marked host %s dead until %s',
|
|
self.urls[i], host.deaduntil)
|
|
else:
|
|
self._hosts_deaduntil[i] = 0
|
|
# If all hosts are dead we should forget that they're dead. This
|
|
# way we won't get completely shut off until dead_retry seconds
|
|
# pass, but will be checking servers as frequent as we can (over
|
|
# way smaller socket_timeout)
|
|
if all(deaduntil > now for deaduntil in self._hosts_deaduntil):
|
|
self._debug_logger('All hosts are dead. Marking them as live.')
|
|
self._hosts_deaduntil[:] = [0] * len(self._hosts_deaduntil)
|
|
finally:
|
|
# super() cannot be used here because Queue in stdlib is an
|
|
# old-style class
|
|
ConnectionPool._put(self, conn)
|